Finite-size effect on the first-order metal-insulator transition in VO[sub 2] films grown by metal-organic chemical-vapor deposition

Journal Article · Sat May 15 04:00:00 EDT 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.47.12900· OSTI ID:6518583

Kim, H K; You, H; Chiarello, R P; Chang, H L.M.; Zhang, T J; Lam, D J ^[1]

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1. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

We studied the finite-size effect on the first-order metal-insulator phase transition and the accompanying tetragonal-to-monoclinic structural transition of VO[sub 2] films. The VO[sub 2] films were epitaxially grown by a metal-organic-chemical-vapor-deposition technique on the (101) growth plane of a 125-A-thick TiO[sub 2] buffer layer which was also epitaxially predeposited on polished sapphire (11[bar 2]0) substrates. The thickness of the VO[sub 2] films in this study ranges from 60 to 310 A. We find that VO[sub 2] films grow isomorphically on the TiO[sub 2] buffer layer resulting in a high degree of epitaxial VO[sub 2] films. We determined structural correlation lengths of the VO[sub 2] films parallel and normal to the growth plane from the x-ray-diffraction widths of VO[sub 2] reflections at room temperature. The structural order parameter associated with the monoclinic distortion and the change in resistivity associated with the metal-insulator phase transition were simultaneously measured using x-ray-diffraction and resistivity measurements. It was found that the transition temperature, width of the transition, and the estimated electronic gap are dependent on the structural correlation length normal to the growth plane. These dependences are discussed in terms of finite-size and substrate effects on the first-order phase transition.

• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6518583
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 47:19; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
CHALCOGENIDES
CRYSTAL-PHASE TRANSFORMATIONS
ENERGY GAP
FILMS
ORDER PARAMETERS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
THERMODYNAMIC PROPERTIES
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
VANADIUM COMPOUNDS
VANADIUM OXIDES